The present invention relates to an apparatus and method for recognizing self-position in a robot system; and, particularly to an apparatus and method for recognizing self-position employing a virtual map divided into directional reflex distance data and cell unit, and a computer-readable recording medium for recording a program containing the method of the invention.
In addition, the present invention is related to self-position recognition technique that has been applied to cleaning robots and robots with artificial intelligence, in which the robots can confirm their positions, based on the inputted data on the construction of a building or a house, using a reflex distance detector that detects 360xc2x0 directional reflex distance and a highly accurate digital compass.
In a conventional method for recognizing self-position in the robot system, there has been employed a camera in order to confirm self-position by recognizing a particular object or a position transmitting marker in order to recognize self-position. However, in the conventional method, there has been a problematic case such that a highly expensive apparatus is needed or self-position recognition per se is not accurate. Especially, the conventional method requires a great deal of calculation for position recognition and there are often errors in the position recognition.
It is, therefore, an object of the present invention to provide an apparatus and method for more accurately and efficiently recognizing a present self-position in a robot system by comparing directional reflex distance information of every direction a digital compass indicates while rotating a laser distance detector which is served to detect laser reflex distance to 360xc2x0 direction with directional reflex distance information from substitute cell positions on a pre-determined virtual map regarding a building structure.
Another object of the present invention is to provide a computer-readable recording medium that records a program for executing the method described above.
In order to achieve the above-described objects, there is provided an apparatus for recognizing self-position in a robot system, the apparatus includes reflex distance detecting unit for outputting a designated signal to each direction obtained by equally dividing 360xc2x0 as designated, detecting a point where the outputted signal reaches a designated object by using the signal reflected and inputted, and based on the detection result, detecting the distance to the object in each direction; direction detecting unit for providing information of absolute direction; and controlling unit for controlling general operation of the reflex distance detecting unit and the direction detecting unit, dividing the region on a virtual map into a cell unit to generate directional reflex distance information per cell, and recognizing the present position by comparing the directional reflex distance information of each cell with the directional reflex distance information from the present position of a detected robot.
In accordance with an aspect of the present invention, there is provided a method for recognizing self-position in a robot system, the method comprising the steps of forming a virtual map consisting of a plurality of cells; outputting a designated signal to each direction obtained by equally dividing 360xc2x0 as designated, and detecting a point where the outputted signal reaches a designated object by using the signal reflected and inputted; detecting distance to the object from each direction based on the detected point from the previous step, and saving the distance in each cell; detecting directional reflex distance information at the present position of the robot; and recognizing the present position of the robot by comparing the directional reflex distance information saved in each cell and the directional reflex distance information at the present position of the robot.
In accordance with another aspect of the present invention, there is provided a computer-readable recording medium storing instructions for executing a method for recognizing self-position in a robot system, the method comprising the steps of: a) forming a virtual map consisting of a plurality of cells; b) outputting a designated signal to each direction obtained by equally dividing 360xc2x0 as designated, and detecting a point where the outputted signal reaches a designated object by using the signal reflected and inputted; c) detecting distance to the object from each direction based on the detected point from the previous step, and saving the distance in each cell; d) detecting directional reflex distance information at the present position of the robot; and e) recognizing the present position of the robot by comparing the directional reflex distance information saved in each cell and the directional reflex distance information at the present position of the robot.
According to the embodiment of the present invention, a self-position recognizing method in a robot system, a robot unit first forms a two-dimensional virtual map based on the analysis on the construction of a house or a building. The robot unit then divides the region on the virtual map into a minimum number of cells, and figures out directional laser reflex distance information on each direction obtained from equally dividing 360xc2x0 by designated values around each cell (i.e., 16 directions if 360xc2x0 is divided by 22.5xc2x0, 32 directions if 360xc2x0 divided by 11.25xc2x0). This information on the position of each cell on the virtual map is later used for position information cell to help a robot to recognize self-position while shifting.
In order for a robot to recognize his self-position or utilize the information on the self-position, he seeks for other expected substitute cells by using direction and actual distance he shifted from the present cell, and selecting a closest cell after comparing each directional laser reflex distance information of the present position with that of other substitute cells aforementioned.
The recognition of self-position according to the present invention is very accurate and efficient since it uses absolute directional reflex information. Especially, cell-divided region indicating method related to position information is very advantages and convenient for a cleaning robot without an operator.